Manually removable crown cap

ABSTRACT

A bottle closing cap is disclosed that is openable merely by a finger pressure on a domed top side of the cap, whereby it is possible to provoke an expansion of a depending, axially preslit cap skirt portion of the cap. The cap can resist overpressure in the bottle because the ends of the skirt segments are stabilized against overlapping, e.g. in that at each slit (6) they are shaped with respective counterphased edges (12,14). Hereby the caps will be mountable by a fully conventional equipment and, despite being easy to open, they will resist a considerable pressure in the bottles.

FIELD OF THE INVENTION

The present invention relates to a closing cap, preferably a bottleclosing cap of the Crown-Cork type. These caps have already proven theirgood qualities with regards to cheapness, facility of handling, closingefficiency and reasonable facility of opening, and it is awell-established practice that special opening means are used foropening the caps, which means in the shape of special cap openers are apermanent part of kitchen equipment and even to a great extension ofpersonal equipment similarly to combs, cigarette, etc. It is fullyacceptable that opening the cap closed bottles by means of cap openersrequires a certain force.

BACKGROUND OF THE INVENTION

However, it has previously been realized that another, simpler method ofopening the caps is possible, viz. by a downwards finger pressureagainst the central area of the cap. This method of opening can be usedwhen the cap is previously prepared in the simple manner that thedownwardly projecting cap skirt is provided with three or more slitsplaced along the circumference of the cap. The skirt portions whichcooperate with the bottle head will hereby appear as segments of e.g.120° or 90°, and if the top surface of the cap is just slightly domed,it will be obtained through the downward pressure on the central area ofthe cap that the individual segments are swung outwards from theirengagement with the bottle neck, such that the cap is loosened from thebottle with no need for a usual cap opener.

This would be a particularly attractive opening method, but it has beenobserved that the slits of the cap skirt diminish the ability of the capto resist a positive pressure in the bottle to such an extent that thistechnique has not been usable in practice. Most bottled products aresubject to a considerable positive pressure in the production phase, andthe caps should also be able to resist such positive pressure in thebottles which may occur later on, e.g. by climatic heat.

SUMMARY OF INVENTION

It is the purpose of the invention to provide a cap closure which may beopened in the said simple manner by depressing a central portion of thecap, and which may however resist such a considerable pressure in thebottle that the cap closure will be usable in practice.

The invention is based on the consideration that the curved cap skirtsegments actually should be able to secure the cap despite a great innerpressure in the bottle, if the segments are in the same firm holdingengagement with the bottle as the usual, unbroken cap skirts, as theround segments are still in a strong holding engagement with the upperportion of the cap. Thorough examinations have shown that the cause ofthe weakened holding engagement is not the segmentation as such, butrather the fact that by the mounting of the capsule and the subsequentradial constriction of its skirt for establishing the holding engagementwith the bottle neck, the individual segments are not compressedperipherally sufficiently for the undulated engagement portions of thecap skirt to assume a fully efficient holding engagement with theexpansion on the bottle neck. The cause hereof is that the segments, attheir free end flanges facing each other, are brought to overlapslightly when the cap skirt is effected to constrict about the bottleneck.

By the invention it is an aim to achieve such a strong closing of thesegmented cap that the closing is efficient in connection with such highinner pressure in the bottles that it is usable in practice inconnection with bottles with positive pressure, e.g. beer bottles.According to the invention this may be realized by shaping the capmembers in such a manner that the material right next to the segmentingslits is embossed to form a serrated or undulated course of theassociated slit edges, such that associated, opposing slit edges areundulated in mutual counter-phase. Even though the material is thin itwill hereby be obtained that the two edges of material at each slit maybe pressed very strongly against each other-without overlapping. The capmay therefore be closed in an entirely normal manner by radialcompression of the skirt while obtaining that each segment remains atits square, e.g. 120°, during the radial compression; this means that bythe downwards and inwards bending they are forced to undergo aperipheral constriction as strong as by non-segmented caps, and thisconstriction is essential for the skirt undulations of the cap to bedeformed further inwards against the bottle neck, thus assuming a strongholding engagement with the downwardly oriented holder surface of thebottle head.

Even though the said observed overlapping of material at the slits isvery small, it seems to be important enough to be responsible for aweakened closing effect, as it occurs that a far stronger closing isobtainable solely by providing that the slit edges, e.g. in the saidmanner, are prevented from sliding over each other, with no furthermodifications whatsoever being necessary for the preparation and theapplication of the caps.

However, the invention also comprises another and at least as importantembodiment for achieving the desired result, viz. an embodiment in whichthe cap skirt is slit from the lower edge along only a partial sectionof the skirt height up to a point near the upper end of the skirt. Whenunslit material is left at this upper edge, this may be sufficient forensuring that the slit edges are stabilized against travelling over eachother when the skirt is folded down. There remains only the problem thatthe thereby continuous upper end portion of the cap skirt will generallycounteract an expansion of the skirt segments by depression of thecentral area of the upper surface of the cap, but this problem may beovercome by a further slit being provided immediately next to each skirtslit and extending over the folding area of the skirt, and from hereboth somewhat downwardly along the skirt, however without reaching thelower edge hereof, and somewhat inwardly along the top surface of thecap, however without reaching the centre thereof.

Hereby the cap will be mounted in a fully stable manner, because thefree edges of the cap skirt segments will be permanently abutting andnot overlapping, while the added slits across the folding area will haveno particular effect by the downwards and inwards folding of the capskirt.

When the central area of the cap is depressed for opening the cap, anoutwards turning of the skirt segments will be provoked as mentionedabove, but now this turning will be diminished by the continuity of theskirt at the top of the downwardly open slits. However, the added slitsacross the folding area will compensate for this fact, entailing thecircular folding area to be expandable in the peripheral direction whenthe area is provoked to effect such an expansion, by the occurrence ofan opening or expansion of these transverse slits. This expansion istransmitted to the cap skirt as a whole, which is thereby further causedto release the locking engagement with the bottle neck. In their normalstate, the transverse slits will not diminish the closing effect of thecap, as they are all but caused to contract or close by the innerpressure of the bottle, which attempts to press the cap dome upwards andthereby causes the cap periphery to contract.

BRIEF DESCRIPTION OF DRAWINGS

In the following the invention is described in more detail withreference to the drawing, in which

FIG. 1 is a perspective view of a plate member for punching out capmembers,

FIG. 2A is a perspective view of a cap member,

FIG. 2B is a perspective view of a cap member like that in FIG. 2Aexcept that the slits have a mutual holding engagement and a radial ribis formed thereon,

FIG. 3 is a side view of a bottle neck with applied cap,

FIG. 4 is a perspective view of a modified embodiment of a cap,

FIG. 5 is a corresponding representation of another such cap,

FIG. 6 is a perspective view of a preferred embodiment of a cap member,modified relative FIGS. 1-3,

FIG. 7 the same, shown in opened condition,

FIG. 8 is a representation of a further embodiment of a cap according tothe invention,

FIG. 9 the same, shown in opened condition,

FIGS. 10 and 11 are perspective views of a modified cap according to theinvention,

FIG. 12 is a perspective view of a further modified cap according to theinvention,

FIGS. 13-15 are sectional views of caps mounted on bottle necks, and

FIGS. 16-17 are sectional views for illustrating the mounting of amodified cap.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

In FIG. 1 is shown a metal plate member 2 from which a number of capmembers, marked by circular fields 4, are to be punched out in aconventional manner. In connection with or preferably prior to thispunching, which is not illustrated in more detail, three outer radialslits 6 are provided in each cap member and extend over the subsequentlyshaped skirt area of the caps with a mutual separation of 120°. Inconnection with the punching of the circular members 4, these areprocessed in a conventional manner by deformation pressing where theouter skirt portions of the caps, designated by 8 in FIG. 2a, arepressed down to a protruding inclined position and provided with thoseskirt undulations 10 which are a characteristic of Crown-Cork caps. Thepressing tools of the pressing apparatus may be modified in such amanner as to shape the opposing slit edges 12 and 14 by each slit withan undulated mutually counterphased course in the immediate proximity ofthe slits 6, such that these edges, as shown in FIG. 2A, will intersectat several points. It should be mentioned, however, that theseundulations are preferably embodied in direct integration with theshaping of the slits 6, viz. by suitable shaping of cutting tools atopposing sides of the members.

Later when the cap member is placed on and fixed onto a bottle, thistakes place as shown in FIG. 3 by a tool 16 being pressed down over thetop of the bottle and forcing the skirt 8 to be folded inwards anddownwards in a fully conventional manner, whereby the lower portions ofthe skirt undulations 10 are caused to engage below an upper expansionon the bottle top for tight sealing thereof.

The application of the tool 16 will entail both the said downwards andinwards folding of the skirt 8 and an associated peripheral compressionof the skirt, whereby the skirt undulations 10 are deformed for furtherengagement against the upper holder expansions of the bottle neck,producing an enforced engagement against this. This latter contributionis weakened if the abutting ends of the segments are allowed to slideslightly over each other in the peripheral direction regardless of theradial impression from the tool 16 being of the same importance all theway round. Such sliding will not occur by the invention, as thecounterphased undulations prevent the edges 12 and 14 from passing eachother, the result being that the cap is applied and deformed for sealingin the very same manner as if it were a usual cap without slits 6.

As a practical illustration of the state of things it may be mentionedthat by testing it has been observed that caps with non-undulated slits6 after application have been able to resist bottle pressure of about 3bar, whereas by quite the same type of application, quite similar capsprovided with counterphased undulated slits have been able to resist apressure of 8-9 bar or more, which is acceptable in connection withbottled drinks containing carbon dioxide.

During the clamping of the caps by the tool 16, the undulatedconfiguration of the slit edges 12 and 14 will be smoothened to someextent, but the smoothing will be progressive in such a manner that asecure mutual abutment of the edges will be permanently maintained. Evenif a total smoothing of the undulations occurs towards the end of thedeformation process, this will happen at such an advanced point of timewhere both the radial and peripheral constriction have taken place, suchthat it makes no significant difference whether the slits are subject toan almost microscopic deplacement over each other in the very lastprocessing phase, and anyway no such tendency is observed. The smoothingin question has the advantageous effect that the extreme and maybenoticably protruding sharp corners at some of the segment ends arepressed to a position in which they present no tearing danger.

The caps are shaped with a slightly domed top side, and afterapplication they may then be opened merely by a downwards pressureagainst the central top side area, the cap skirt segments hereby beingcaused to swing outwards and thereby to release the holding engagementwith the bottle neck. The caps may perfectly well be adapted to beingapplicated so as to resist a great pressure in the bottles and still beopenable already by a suitably strong downwards finger pressure againstthe central cap lid portion. It must be considered in this connectionthat the great pressure which the caps must be able to resist does notnecessarily occur in the situation where the bottles are opened.

By the embossing, the cap members should be provided with a noticeablydomed top side, viz. such that this top side, which will be considerablystraightened during application and fixing of the caps as a consequenceof the downwards folding and pulling of the skirt portion, will still besufficiently domed thereafter for being depressible for opening of thecap.

In FIG. 2D it is shown that the slits 6' may be shaped in such a mannerthat a mutual holding engagement will occur between the abutting segmentedges to counter pull effects in the peripheral direction of the skirt,which may be significant for preventing the occurrence of a slightradial expansion of the downwardly and inwardly folded cap skirt afterremoval of the application tool 16, which could weaken the holdingeffect of the cap. There will then merely occur the associated problemthat attempts to open the cap by depressing its central portion will notprovoke the aimed outwards swinging of the skirt segments, when theseare maintained end flange by end flange also during the outwardsswinging actuation of the segments.

However, according to the invention it will yet be possible to achieve awell controlled opening of the cap, when, as shown in FIG. 2B, this isprovided with a formed radial rib 18, extending along the top side ofthe cap and somewhat down the skirt near one side of the slit 6'. Wheneach slit is provided with such a rib at one side, but not at the other,a pressure on the cap top will entail a stronger outwards swingingactuation of the cap skirt at that side of the slits which is providedwith ribs, and hereby the said engagement will be sufficiently releasedfor a subsequent release of the segment ends from each other and afurther outwards swinging for releasing the cap. By this embodimentthere should not occur too pronounced undulations along the slit edges,as the engagement may then be difficult to release.

The invention comprises furthermore another cap type, where the skirt isonly provided with two opposed slits, i.e. with two segments each of180°. Hereby each segment is in a quite strong holding engagement withthe bottle neck, and such a cap cannot be opened just by a pressure onthe top side. However, the cap becomes very easy to open by means of aregular cap opener; so easy that it proves possible to open a fullyclosed cap by means of a short `jimmy`in the shape of a web portionprotruding from the cap itself and shaped as an integrate part thereof.This is illustrated by a couple of examples, cf. FIGS. 4 and 5.

The cap shown in FIG. 4 has its skirt provided with two diametricallysituated slits 20, and one of the skirt segments thus produced isprovided at its centre with a protruding web which is bent down togetherwith the skirt in the mounted condition of the cap, and thereby forms anarched opening handle 22, which may be immediately gripped by a fingerand tipped outwards and upwards, whereby the cap is folded along theline 24 shown in dots, such that it is easy to remove thereafter.Because of the arched cross sectional shape the web 22 is sufficientlyrigid for transmitting the necessary force, even if it made from thesame, relatively thin plate material as the cap itself. It may bepreferred in practice that such an opening handle 22 be provided on bothopposed segments.

FIG. 5 shows another embodiment, where the web is shaped as a protrudingstrip element 25 which may be bent or is bent in order to form a sort ofjimmy supported against the upper side area of the cap skirt and beinggrippable by a finger. Because of the upper abutment as shown at 26 arather well controlled opening sequence is obtained.

The cap member shown in FIG. 6 is a more ordinary member, which,similarly to the embodiment according to FIGS. 1-3 is well suited forbeing produced and used as a usual Crown-Cork cap, only with the optionof being opened by depression. It has shown that the embodimentaccording to FIGS. 1-3 may present difficulties as to a permanentsealing of the bottle closing at a high inner bottle pressure,regardless of the sealing effect being considerably better than with thepreviously known embodiments of manually openable caps. The cause hereofseems to be that the slits 6, see FIG. 2A, extend entirely up to thefolding area of the caps, whereby the skirt lacks a bit of stabilizationagainst expansion at an occurring upwardly directed pressure on the cap.

By the embodiment according to FIG. 6 this is improved by the slit notquite reaching the folding area; an upper skirt portion 30 is leftcontinuous. This has been proven sufficient for the two edges of theslit being stabilized in such a manner that by the common downwardsfolding they remain right opposite from each other, i.e. withoutoverlapping, and it is therefore less necessary to produce those edgeundulations that are disclosed in connection with FIGS. 2A and 2B, eventhough these undulated edges will still be preferred. Furthermore, thecontinuous portion 30 stabilizes against an outwards swinging of theskirt segments subsequently to an upwards pressure against the capsurface from inside the bottle, i.e. the cap closes quite strongly.

The cap is indeed correspondingly more difficult to open by pressurefrom above, but this may be countered by adding the shown additionalslits 32, preferably immediately next to the slits 6'. These slits 32extend across the folding area of the of the skirt and therefromdownwards to a certain distance above the lower edge of the skirt aswell as a certain distance inwards, e.g. half way to the centre of thecap plate member. It is important that these slits do not perforate thebottom of the skirt, as the said stabilizing effect on the skirtsegments would then be lost. The segmentation which occurs by adding theslits 32 will not weaken the cap as to its holding effect against theinner bottle pressure, as the skirt segments do not become substantiallyeasier to swing out by this addition, but the added slits willfacilitate the manual opening of the cap considerably. As the capsurface is domed, the inner pressure will effect a contraction of theroundgoing folding area of the cap which cannot take place, but by adownwards operation pressure the same area will be brought to expand,whereby the slits 32 open slightly, as shown exaggeratedly at 33 in FIG.7.

Simultaneously, the skirt segments will be caused to swing out, wherebyalso the slits 6' open, however less that by the embodiment according toFIGS. 1-3; however, the opening of the slits 32 will contributenoticeably to an outwards sliding of the skirt segments and thereby to arelease hereof from their engagement with the bottle, such that despitethe improved holding effect, the cap is still suitably easy to open inthe disclosed manner.

The strip-shaped skirt portion 34 between the different pairs of slits6' and 32 will twist slightly by the opening, and it would seem that itis a condition for the good openability that these strip portions besufficiently narrow to be affected to perform such a twisting whichfurthers the opening of both types of slits 6' and 32.

Also by the embodiment according to FIG. 6 and 7 there may--as in FIG.2B--advantageously be provided rib formations 18 for enforcing thetipping action on the skirt segments by the pressing opening of the cap.It is enough to mention here that these ribs may have many differentconfigurations, and that the invention is not limited to any definedconfiguration of the ribs; they may be more or less evenly distributed,e.g. gathered in groups facing the individual segments.

In FIG. 8 is shown a modified embodiment of the cap, where the slits 6or 31 are embodied in such a manner that they extend almost out to ordown to the free end of the cap skirt, but exactly without perforatingthe outermost edge portion. At the outer slit ends in question atransverse slit is added, possibly in the shape of a punched hole 30,whereby a narrow, continuous strip portion 32 is formed in the undulatedlower edge course of the skirt across the outer end of the slit 6. Thepresence of this continuous strip portion may be sufficient to ensurethat the opposed skirt edges at the slit 6 cannot be pressed past eachother by the constriction of the cap skirt about the bottle neck, suchthat the said undulations will be omittable.

Ideally the width of the strip portion 32 should be so small that thisportion is broken when the centre of the cap is depressed, but this isdifficult to obtain in a well controlled manner, nor is it necessary, asthe expansion force which will be transmitted to the skirt by thisdepression will serve instead for straightening the undulated portion,which the strip portion 32 is following, whereby it is possiblenevertheless to obtain the skirt expansion that conditions a release ofthe cap, such as it is shown in FIG. 9.

FIGS. 10 and 11 show, in respective closed and opened positions, amodified cap having slots 6' and ribs 18' as in FIG. 2B, only with theslots extended inwardly over the cap and the ribs 18' extended down tothe edge of the cap

As far as the punching of the slits is concerned, these may as suggestedbe shaped simultaneously to the punching of the cap members 4, but forseveral reasons it is preferred to shape them during a separateoperation prior to this punching. This entails that the punchingapparatus may be used without changing, whereby the entire productionand application line may be used without change, only with themodification that a special slit cutter unit is inserted before thepunching machine. The thin plate members with the preprinted cap areasmay then alternatively be conveyed directly to the punching machine,when a series of conventional caps is to be produced.

The shaping of the dome on the cap top surface and/or the disclosedradial rib portions may in the same connection take place in theslitting unit, but with a rather important production it is probablybest to effectuate also this embossing in the embossing and punchingmachine. It could even be tolerated that Crown-Cork caps in general beprovided with the dome that is desired, when the members are furtherlyprocessed accordingly to the invention.

In FIG. 1 the letter L suggests that cutting lines 6, which perforatethe edge of the cap members 4, may be provided advantageously with anangled end portion, as the cutting line itself may then be provided bypunching up a triangular web, which may later be pressed back to plane.In this manner the cutting lines may be produced without any strainsoccurring in the material.

By the embodiment shown in FIG. 12 slits 6 are used which projectinwards over part of the top surface of the cap, but have a shortinterruption 40 precisely in the upper rim line of the cap, such thatthe cap goes round uninterrupted along this line. The rim area attemptsto expand when the domed cap top surface is depressed, and the areas 40may ideally be arranged so as to break when thus actuated, which,however, requires an extremely accurate working if the cap also has tokeep its tightly sealing shape. It is indicated that between the slits 6further slits 42 are provided in the cap top surface near the rimhereof; these slits will contribute to facilitate the expansion of therim area, and optionally they may even extend out over the rim area.

Slits occurring in the cap top surface will of course imply that a coverlayer be found at the underside of the caps so as to seal the slitsuntil the cap is opened. In this same connection it may be importantthat this sealing layer, which is already known as a gasket layer forsealing against the top surface of the bottle neck, be embodied in anadditionally sealing manner, viz. by being provided, as shown in FIG.13, with a cylinder portion 44 projecting down into the bottle neck andbeing pressed out against the inner side of the bottle neck area by theinner bottle pressure so as to obtain the desired additional sealing.Alternatively an insertion member 46 may be used as shown in FIGS. 14and 15 with and without inner pressure in the bottle, respectively.

By the invention it is of great importance that usual machinery can beused for mounting the caps. It should be noted, however, that withcertain cap qualities the disadvantage may occur that by the downwardsactuation of the skirt for folding it in, an extrusion of material fromthe lid plate member may occur, when this plate member is of the saiddomed shape. Hereby the lid plate member is more or less flattened out,such that it may possibly become too weak for effecting the pressopening function.

However, this difficulty may be overcome according to the invention withno required modification of the application tools, simply by an adaptedembodiment of the caps members, which is illustrated in more detail inFIGS. 16-17. In these figures is shown a bottle neck 50 placed below aquite conventional closing tool 52 consisting of an inner tubular piston54 which is downwardly projectable for fastening the rim of a cap member56, loosely placed on the bottle opening, against the top edge of thebottle opening, and a surrounding tube piston 58, which may subsequentlybe projected down for pressing the cap skirt, cf. also FIG. 3.Regardless of the inner tube piston holding the cap firmly pressedagainst the bottle opening, the depression of the outer stamp 58 mayprovoke an extrusion of material from the top side of the cap, when thisis domed, whereby the said undesired flattening may occur.

However, the cap member 56 is provided with an outer roundgoingdepression 60 which exactly fits the inner edge position of the innertube piston 54, whereby the said extrusion of material from thee topside of the cap 56 will be prevented such that the cap top may remaindomed as desired.

The depression 60 may be produced in the same process as the punching ofthe cap members 4, cf. FIG. 1, i.e. by producing a suitable punchingtool once and for all, such that the problem disclosed here may beprevented in a very simple and cheap manner.

I claim:
 1. A closing cap for a bottle having an upper expansion aboutan opening to be closed by said cap, said closing cap comprising a capplate member having an outer edge portion projecting downwards andshaped for engagement below said upper expansion member of said bottle,said cap having a skirt portion which is shaped with a segmenting axialslitting in at least two areas around its circumference wherein saidslits in the cap skirt portion are shaped in such a manner that abuttingend edges of adjacent segments of the skirt portion at each slit arestabilized against being displaceable to mutual overlapping by a skirtportion constriction which is provoked by the mounting of the cap on thebottle and wherein said abutting end edges of adjacent segments areprovided with an undulated surface course, extending principally incounterphase with one another.
 2. A closing cap according to claim 1,wherein an upper portion of said cap plate member is domed so that itcan be depressed for expanding said skirt portion, and wherein the capis provided with at least one pressed-up radial rib formation, whichfrom the cap plate member extends out over the rim thereof and furtherdown along the skirt portion at ane side, but not immediately at theother side of one of said slits.
 3. A cap according to claim 1, whereinthe slits in the skirt portion have their upper ends situated at acertain distance below the upper edge of the skirt portion, and saidcap, in the immediate proximity of the slits, being provided withfurther slitting in the shape of cutting lines, which from an area ofthe cap plate member extend out over the rim of this plate member andfurther down on the skirt, however without completely reaching the loweredge thereof.
 4. A cap according to claim 1, wherein at least one of theskirt segments at its bottom is extended to form a swingable openinghandle for purely manual opening of the cap.
 5. A cap according to claim1, wherein the slits of the cap skirt portion are not continuedcompletely down to the lower edge of the skirt portion, but only to anarea very near this lower edge.
 6. A cap according to claim 5, whereinat the lower end of the slits an opening is provided in the cap skirtportion, which opening extends in the horizontal direction across anundulated area of the skirt portion, such that by the opening action,the skirt portion may expand by a straightening of the continuousundulated strip area left at the lower edge of the cap.
 7. A capaccording to claim 1, further comprising an inner sealing gasket forabutting the bottle neck opening, said gasket, for relieving the innerpressure up against the manually openable cap, is formed as a bowlmember projecting downwards into the bottle opening and the sides ofwhich being pressed out against the inner side of a bottle neck of thebottle by the bottle pressure directed against the bottom of the bowlmember.
 8. A cap according to claim 1, wherein near the periphery of thecap plate member, the cap is provided with an annular outer depression,which makes it possible by the mounting of the cap for an adjacenttubular holder member to engage a vertical wall portion of thisdepression for fastening the on said bottle.
 9. A cap according to claim1, further comprising an inner sealing gasket for abutting a neckopening of the bottle, wherein said sealing gasket is provided with asealing collar projecting into the neck opening of said bottle and beingconically constricting in the downwards direction.